Field of the Invention
This invention relates to the use of optionally ethoxylated and/or propoxylated partial esters of oligoglycerols obtainable by condensation of 2 to 20 glycerol molecules with optionally hydroxy-substituted C.sub.2-18 fatty acids as pigment dispersants for water-based lacquer dispersions.
Discussion of Related Art
Partial esters of oligoglycerols obtainable by condensation of 2 to 20 glycerol molecules with fatty acids are known, cf. Fette, Seifen, Anstrichmittel, Vol. 88, pages 101 to 106 (1986); DE-C 25 11 807. These partial esters are often used as internal lubricants and/or antistatic additives for plastics.
Anionic dispersants are frequently used as pigment dispersants for water-based lacquer dispersions, as are nonionic dispersants based on adducts of ethylene oxide and/or propylene oxide with compounds containing active hydrogen atoms, cf. H. Kittel (ed.), Lehrbuch der Lacke und Beschichtungen, Vol. III, pp. 250 to 258, Verlag W. A. Colomb, Berlin (1976), or low molecular weight polyacrylic acid salts, cf. DE-A 3,318,595.
However, the use of the known dispersants in water-based lacquer dispersions is attended by various disadvantages. More particularly, unwanted foaming occurs to an increased extent in the water-based lacquer dispersions.